diff --git a/Dockerfile b/Dockerfile
index 8b7d4e1..5beaf95 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,6 +10,8 @@ RUN go build
 
 FROM alpine:3.15
 
+LABEL LastUpdate="2022-04-04"
+
 COPY --from=builder /app/telegram-group2mastodon /bin/telegram-group2mastodon
 
 RUN apk -U --no-cache upgrade